Femtosecond laser induced simultaneous functional nanomaterial synthesis,in situ deposition and hierarchical LIPSS nanostructuring for tunable antireflectance and iridescence applications

Femtosecond laser induced periodic surface structures(LIPSSs)are excellent biomimetic iridescent antireflective interfaces.In this work,we demonstrate the feasibility to develop tunable iridescent antireflective surfaces via simultaneous synthesis of functional metal-oxide nanomaterials,in situ deposition and hierarchical LIPSSs nanostructuring by means of femtosecond laser ablation(fs-LA)of tungsten(W)and molybdenum(Mo)in air.Adjusting the scanning interval from 1μm to 20μm allows the modulation of particle deposition rates on LIPSSs.Diminishing the scan interval enables a higher particle deposition rate,which facilitates the development of better UV-to-MIR ultrabroadband antireflective surfaces with a less pronounced iridescence.Through comparing the reflectance of hierarchical LIPSSs with different densities of loosely/tightly deposited particles,it is found that the deposited WO_(x)and MoO_(x)particle aggregates have high UV-to-MIR ultrabroadband absorbance,especially extraordinary in the MIR range.Loosely deposited particles which self-assembly into macroporous structures outperform tightly deposited particles for ultrabroadband antireflective applications.The presence of loosely deposited MoO_(x)and WO_(x)particle absorbers can cause up to 80%and 60%enhancement of antireflectance performances as compared to the tightly particle deposited LIPSSs samples.One stone of"fs-LA technique"with three birds of(particle generation,in situ deposition and LIPSS hierarchical nanostructuring)presented in this work opens up new opportunities to tune the reflectance and iridescence of metallic surfaces.

赏世间美好事物 藏轩尼诗耀眼佳酿——轩尼诗X．O最新呈现典藏版“Iridescence”

懂得欣赏优雅和尊贵的品位人士,应该不会忘记2007年在北京举行的顶级私人物品展,更不会忘记在那次美的盛宴上,轩尼诗X.O发布的全球典藏版"Magnificence"。

三疣梭子蟹十足目虹彩病毒1 SYBR Green I荧光定量PCR检测方法的建立及初步应用

为建立十足目虹彩病毒1(decapod iridescent virus 1,DIV1)的SYBR GreenⅠ荧光定量PCR检测方法,根据DIV1的MCP和ATPase基因序列,设计并筛选出引物,以制备的DIV1阳性质粒标准品为模板构建标准曲线,建立DIV1的SYBR Green I qPCR方法,并对该方法进行临床初步应用。结果显示,建立的qPCR方法阈值循环数(cycle threshold value,Ct)与标准品拷贝数的对数线性关系良好,标准曲线相关系数(R^(2))为0.999;对DIV1阳性的虾蟹核酸样本能够进行特异性扩增,但对传染性脾肾坏死病毒(infectious spleen and kidney necrosis virus,ISKNV)和白斑综合征病毒(white spot syndrome virus,WSSV)阳性核酸样本均无扩增;最低检测限为9.77 copies/μL;Ct值的组内和组间变异系数均小于1%。运用该方法对70份疑似感染DIV1的虾蟹类样本进行DIV1检测,该方法阳性率为48.57%,与套式PCR检测方法的阳性率一致;利用建立的方法对DIV1阳性三疣梭子蟹的血淋巴、肝胰腺及心脏等组织进行定量检测分析,结果显示各组织中均存在DIV1,其中血淋巴中DIV1平均拷贝数最高。研究表明,建立的SYBR GreenⅠ荧光定量PCR方法特异性强、灵敏度高、重复性好,可用于对DIV1的快速、定量检测,对十足目虹彩病毒病的诊断和防控具有重要意义。

Irregular LIPSS produced on metals by single linearly polarized femtosecond laser

Currently,supra-wavelength periodic surface structures(SWPSS)are only achievable on silica dielectrics and silicon by femtosecond(fs)laser ablation,while triangular and rhombic laser induced periodic surface structures(LIPSS)are achievable by circularly polarized or linear cross-polarized femtosecond laser.This is the first work to demonstrate the possibility of generating SWPSS on Sn and triangular and rhombic LIPSS on W,Mo,Ta,and Nb using a single linearly polarized femtosecond laser.We discovered,for the first time,SWPSS patches with each possessing its own orientation,which are completely independent of the light polarization direction,thus,breaking the traditional rules.Increasing the laser power enlarges SWPSS periods from 4–6μm to 15–25μm.We report a maximal period of 25μm,which is the largest period ever reported for SWPSS,~10 and~4 times the maximal periods(2.4μm/6.5μm)of SWPSS ever achieved by fs and ns laser ablation,respectively.The formation of triangular and rhombic LIPSS does not depend on the laser(power)or processing(scan interval and scan methodology)parameters but strongly depends on the material composition and is unachievable on other metals,such as Sn,Al,Ti,Zn,and Zr.This paper proposes and discusses possible mechanisms for molten droplet generation/spread/solidification,Marangoni convection flow for SWPSS formation,and linear-to-circular polarization transition for triangular and rhombic LIPSS formation.Reflectance and iridescence of as-prepared SWPSS and LIPSS are characterized.It was found that besides insufficient ablation on W,the iridescence density of Ta-,Mo-,Nb-LIPSS follows the sequence of melting temperatures:Ta>Mo>Nb,which indicates that the melting temperature of metals may affect the regularity of LIPSS.This work may inspire significant interest in further enriching the diversity of LIPSS and SWPSS.

Invertebrate Iridovirus Modulation of Apoptosis

Programmed cell death （apoptosis） is a key host response to virus infection. Viruses that can modulate host apoptotic responses are likely to gain important opportunities for transmission. Here we review recent studies that demonstrate that particles of Invertebrate iridescent virus 6 （IIV-6） （Iridoviridae, genus Iridovirus）, or an IIV-6 virion protein extract, are capable of inducing apoptosis in lepidopteran and coleopteran cells, at concentrations 1000-fold lower than that required to shut-off host macromolecular synthesis. Induction of apoptosis depends on endocytosis of one or more heat-sensitive virion component（s）. Studies with a JNK inhibitor （SP600125） indicated that the JNK signaling pathway is significantly involved in apoptosis in IIV-6 infections of Choristoneurafumiferana cells. The genome of IIV-6 codes for an inhibitor of apoptosis iap gene （193R） that encodes a protein of 208 aa with 15% identity and 28% similarity in its amino acid sequence to IAP-3 from Cydia pomonella ganulovirus （CpGV）. Transcription of IIV-6 iap did not require prior DNA or protein synthesis, indicating that it is an immediate-early class gene. Transient expression and gene knockdown studies have confirmed the functional nature of the IIV-6 lap gene. We present a tentative model for IIV-6 induction and inhibition of apoptosis in insect cells and discuss the potential applications of these findings in insect pest control.

The Biology of Chilo Iridescent Virus

Chilo iridescent virus (CIV) is the type species for genus Iridovirus, and belongs to the family Iridoviridae. Since the discovery of CIV in 1966, many attempts were made to elucidate the viral genome structure. The virions contain a single linear ds DNA molecule that is circularly permuted and terminally redundant. The genome of CIV has been entirely sequenced. The CIV virion consists of an unusual three-layer structure containing an outer proteinaceous capsid, an intermediate lipid membrane, and a core DNA-protein complex containing the genome. CIV has a broad host spectrum and has, in general, a limited mortality effect on its hosts. Up to now there have been several studies about CIV describing its structure, ecology, and molecular biology. In this review study we present all these studies together to describe the CIV.

Morphological structure and optical properties of the wings of Morphidae

The morphological structure and optical properties of the wings of 14 species of Morphidae have been investigated. Most of the scales of the iridescent species of Morphidae （Lepidoptera） present a very particular structure. The ground scales, responsible for the major part of the optical properties, are covered by a very regular set of longitudinal ridges. The ridges themselves are constituted by a superposition of lamellae that act locally as a multilayered structure. This very specific morphology leads to both interferences and diffraction effects. The first one is responsible of the brilliant blue coloration of the males, while the second one diffracts this colored light at a very large angle. These two phenomena give to the butterfly a very effective long-range communication system. The morphological characteristics of the scales of the various species are presented in detail. Two types of optical measurement were performed on the iridescent wings of 14 different species of Morphidae： spectroscopic measurements under various incidences and gonioscopic measurements for a given incidence angle and wavelength. The first allows a determination of the index of refraction of the cuticular material. The second leads to the drawing of spatial diffraction maps. It shows that most of the reflected light is diffracted laterally over a very large angle （90° 〈 0 〈 120°, according to the different species） and that this repartition depends of the polarization of incident light. As predicted by previous calculations, the dissymmetric structure of the ridge is responsible for the separation of the polarization modes in the various diffraction orders.

Signal or cue: the role of structural colors in flower pollination

Angle dependent colors, such as iridescenee, are produced by structures present on flower petals changing their visual appearanee. These colors have been proposed to act as signals for plantinsect communication. However, there is a paucity of behavioral data to allow for interpretations of how to classify these colors either as a signal or a cue when con sidering the n atural con ditions under which pollination occurs. We sampled flowers from 6 plant species across various viewpoints looking for changes in the visual appearanee of the petals. Spectral characteristics were measured with different instruments to simulate both the spectral and spatial characteristics of honeybee's vision. We show the presenee of color patches produced by angle dependent effects on the petals and the calyx of various species;however, the appearance of the angle dependent color patches significantly varies with viewpoint and would only be resolved by the insect eye at close distances. Behavior experiments with honeybees revealed that pollinators did not use angle dependent colors to drive behavior when presented with novel flower presentations. Results show that angle dependent colors do not comply with the requirements of a signal for plant-pollinator communication since the information transmitted by these colors would be unreliable for potential, free-flying pollination vectors. We thus classify angle dependent colors produced by micro- and ultra-structures as being a cue (a feature which has not evolved for communication), and observe no evidence supporting claims of these angle dependent colors having evolved as visual signal.

High refractive index of melanin in shiny occipital feathers of a bird of paradise

Male Lawes’s Parotia,a bird of paradise,use the highly directional reflection of the structurally colored,brilliant-silvery occipital feathers in their courtship display.As in other birds,the structural coloration is produced by ordered melanin pigmentation.The barbules of the Parotia’s occipital feathers,with thickness,3 μm,contain 6–7 layers of densely packed melanin rodlets(diameter,0.25 μm,length,2 μm).The effectively,0.2 μm thick melanin layers separated by,0.2 μm thick keratin layers create a multilayer interference reflector.Reflectance measurements yielded peak wavelengths in the near-infrared at,1.3 μm,i.e.,far outside the visible wavelength range.With the Jamin-Lebedeff interference microscopy method recently developed for pigmented media,we here determined the refractive index of the intact barbules.We thus derived the wavelength dependence of the refractive index of the barbules’melanin to be 1.7–1.8 in the visible wavelength range.Implementing the anatomical and refractive index data in an optical multilayer model,we calculated the barbules’reflectance,transmittance and absorptance spectra,thereby confirming measured spectra.

Heightened condition dependent expression of structural coloration in the faces,but not wings,of male and female flies

Structurally colored sexual signals are a conspicuous and widespread class of ornament used in mate choice,though the extent to which they encode information on the quality of their bearers is not fully resolved.Theory predicts that signaling traits under strong sexual selection as honest indicators should evolve to be more developmentally integrated and exaggerated than nonsexual traits,thereby leading to heightened condition dependence.Here,we test this prediction through examination of the sexually dimorphic faces and wings of the cursorial fly Lispe cana.Males and females possess structural UV-white and golden faces,respectively,and males present their faces and wings to females during close-range,ground-based courtship displays,thereby creating the opportunity for mutual inspection.Across a field-collected sample of individuals,we found that the appearance of the faces of both sexes scaled positively with individual condition,though along separate axes.Males in better condition expressed brighter faces as modeled according to conspecific flies,whereas condition scaled with facial saturation in females.We found no such relationships for their wing interference pattern nor abdomens,with the latter included as a nonsexual control.Our results suggest that the structurally colored faces,but not the iridescent wings,of male and female L.cana are reliable guides to individual quality and support the broader potential for structural colors as honest signals.They also highlight the potential for mutual mate choice in this system,while arguing for 1 of several alternate signaling roles for wing interferences patterns among the myriad taxa which bear them.